Positive-flow valve

ABSTRACT

A closed system, spikeless, positive-flow valve device includes a body defining an internal cavity. At the proximal end of the body is an opening which is preferably sufficiently large to receive an ANSI standard tip of a medical implement. The valve includes a plastic, resilient silicon seal which fills the upper cavity and opening with an oval seal cap having a slit. The opening presses the oval seal cap to keep the slit closed in the decompressed state. The slit opens as the nose of the medical implement compresses the seal into the cavity and the seal cap is free from the opening. The housing also includes a fluid space which facilitates fluid flow between the medical implement and a catheter tip. The fluid space within the valve automatically and reversibly increases upon insertion of the medical implement into the cavity and decreases upon withdrawal of the medical implement, such that a positive flow from the valve toward the catheter tip is effected upon withdrawal of the medical implement, thereby preventing a flow of blood from a patient into the catheter when the medical implement is removed from the valve.

This application is a continuation of application Ser. No. 08/767,587filed on Dec. 16, 1996 now abandoned.

FIELD OF THE INVENTION

This invention relates generally to a medical valve, and in particularto a positive flow valve which, when connected between a medicalimplement and a catheter to facilitate fluid flow therethrough, inducesa positive flow of fluid through a tip of the catheter from the valveupon disconnection of the medical implement, thereby eliminating theproblem of blood-clogging or clotting in the catheter.

BACKGROUND OF THE INVENTION

The manipulation of fluids for parenteral administration in hospitalsand medical settings routinely involves the use of connectors and valvesfor facilitating the movement of fluids between two points. Fluidconnectors and valves typically employ needles or luers to pierce aseptum or seal covering sterile tubing or to pierce a septum or seal ofa medicament container of fluid. Fluid then passes from the container orfluid-filled tubing into a syringe or second set of tubing. Since theready passage of fluids through the connectors and valves is oftencritical to patient survival, it is imperative that the connectors andvalves function reliably and repeatedly. Connectors and valves thatmalfunction during use may be life-threatening.

Many connectors or valves, especially those employing several mechanicalcomponents, have a relatively high volume of fluid space within them.There is potential for the creation of a “dead space” (i.e. an increasein the fluid containment area which will cause fluid within the patientto be drawn therein) in the fluid space during removal or disconnectionof the tubing or other medical implements such as conduits, syringes, IVsets (both peripheral and central lines), piggyback lines, and similarcomponents which can be used in connection with a medical valve.Withdrawal of the medical implement creates a suction force which drawsfluid back toward the valve in a phenomenon known as “backflash.” Thisis particularly troublesome in the case where the valve is connectedthrough a catheter to a patient. A suction force is generated by thewithdrawal of the medical implement which draws blood from the patientinto the catheter. This blood clot and clog the catheter near its tip,rendering it inoperable, and may even result in a clot of blood in thepatient, which may prove fatal. Attempts to avoid backflash by coatingthe inner surface of the catheter near its tip in order to prevent bloodfrom sticking to the interior surfaces of the catheter and clogging ithave not been successful.

The risk of blood clogging of the catheter is significantly heightenedwhere the inner diameter of the catheter is small (e.g., 27 gauge).These small catheters have the advantage, however, that they reduce thetrauma and discomfort caused by insertion into a patient. Because thesecatheters have a very small passage therethrough, even a small suctionforce may draw sufficient amount of fluid back through a catheter towardthe valve to introduce blood into the catheter tip, which blood may clogthe catheter's passage. This back flow is hereinafter referred to as anegative flow. FIG. 1 shows an example of a catheter 50 having a smallportion near the tip 52 that is inserted into the patient, and a valve54 connected between one end of the catheter and a medical implement 56.The problem associated with the creation of “dead space” or a drawing offluid from the catheter towards the valve is illustrated by this Figure.As illustrated therein, when the tip or nose of the medical implement 56is withdrawn from the valve 54, the space previously occupied by theimplement 56 becomes “dead space.” This newly created space has a lowerpressure than the fluid within the valve, catheter and patient, suchthat fluid is drawn into that space, and thus travels from the patientin the direction of the dead space. To avoid blood from being drawn intothe catheter, a zero flow or a positive flow, defined as flow or fluiddisplacement directed from the valve through the catheter tip to thepatient, must be effected at the time the medical implement iswithdrawn. For a sufficient margin of safety, a positive flow toward thepatient is desirable.

To avoid negative flow or backflash, healthcare workers presentlypractice the method of disconnecting the valve and simultaneouslytransferring fluid through the catheter by manipulating the medicalimplement to induce positive flow. This method is clumsy and difficult,and may result in an inaccurate transfer of medicament.

One way to induce a positive flow in the catheter is illustrated inFIGS. 2a and 2 b. Here, the proximal end of a valve 180 is enclosed witha stylet or displacer 182 upon withdrawal of the medical implement (notshown). An elongated portion 184 of the stylet 182 takes up at least aportion of the fluid space, thereby reducing the volume of the fluidspace, and may eliminate the dead space therein. The elongated portion184, however, must be sufficiently long to displace more fluid than thatvolume of fluid which may be drawn from the catheter towards the valveby the withdrawal of the implement, and hence may be difficult toconstruct for proper performance. The use of the stylet 182 furtherrequires an additional step that may be overlooked by the nurse and thestylet 182 may be misplaced or lost. In addition, this specific type ofvalve 180 has many significant drawbacks, among them the fact that itdoes not have a seal with a swabbable surface that can be swabbed aftereach use for sterility.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided a positiveflow valve which is advantageously utilized between a catheter andanother medical implement, and with which the flow of a fluid betweenthe implement and catheter (and a patient within which the catheter isemployed). The valve of this invention has several features, no singleone of which is solely responsible for its desirable attributes.

In general, the positive flow valve of the present invention has theattributes of safety, positive flow for eliminating dead space, reliableand repeatable performance, simplicity of manufacture and use, a sealfor use in establishing fluid flow which need not be pierced with asharp spike or cannula, suitability of high pressure applications, andemployment of a valve that is swabbable after use to provide sterilityand has a fluid-tight seal at high pressure.

The present invention is a swabbable, needle-less, positive flow valvethat has a fluid space which automatically expands upon insertion of amedical implement and contracts upon withdrawal of the medicalimplement. When the valve is connected to a catheter, it induces apositive flow from the valve to the catheter tip upon disconnection ofthe medical implement to avoid the potential problems of blood-clogging.After use, the valve is swabbed in the conventional manner with asuitable substance to maintain sterility. The design of the valve avoidsaccidental needle or spike sticks. The valve is particularly suited forapplications with a catheter where it is desirable to avoid backflash,but may be used for other applications as well.

Preferably, the valve includes a housing having a first end adapted forreceiving one end of medical implement, and having a second end incommunication with a catheter. The valve includes means for establishinga fluid flow path through the housing and between the medical implementand the catheter, and which is also useful in occluding the flow paththrough the housing and thereby preventing fluid flow between themedical implement and catheter.

Preferably, this means comprises a seal movably positioned within thehousing. The seal has a passage therethrough which defines, in at leastone area, a fluid containment area. The seal has a first end adapted forengagement by the medical implement. In a first position, the passagethrough the seal is closed at its first end, and in a second position,when the medical implement is utilized to press the seal distally withinthe housing of the valve, the passage through the valve is opened.

Most importantly, when the medical implement is utilized to press theseal distally and establish fluid flow therethrough, the fluidcontainment area therein increases in total volume, thereby retaining afluid volume therein. When the medical implement is retracted from thevalve, the seal returns to its position wherein the passage is closed atthe proximal end thereof, and the volume of the fluid containment areais reduced. This reduction in fluid containment volume results in avolume of fluid being forced towards the catheter (i.e. a positive flowis established).

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of this invention, illustrating all itsfeatures, will now be discussed in detail. These embodiments depict thenovel and nonobvious method and valve of this invention shown in theaccompanying drawings, which are for illustrative purposes only. Thedrawings include the following Figures, with like numerals indicatinglike parts:

FIG. 1 is a schematic cross-sectional view of a valve forming a fluidconnection between a syringe and a catheter.

FIGS. 2a and 2 b illustrate a prior art valve which includes a stylethaving an elongated portion after use to induce a positive flow.

FIG. 3 is a schematic cross-sectional view of a roller-clamp valve whichmay be manually activated to induce a positive flow through a cathetertip from the valve.

FIG. 4 is a longitudinal cross-sectional view of the first embodiment ofthe positive-flow valve of this invention before compressing the seal.

FIG. 5 is a longitudinal cross-sectional view similar to FIG. 4 showingthe valve during compression of the seal.

FIG. 6 is a longitudinal cross-sectional view of the second embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 7 is a longitudinal cross-sectional view similar to FIG. 6 showingthe valve during compression of the seal.

FIG. 8 is a longitudinal cross-sectional view of the third embodiment ofthe positive-flow valve of this invention before compressing the seal.

FIG. 9 is a longitudinal cross-sectional view similar to FIG. 8 showingthe valve during compression of the seal.

FIG. 10 is a longitudinal cross-sectional view of the fourth embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 11 is a longitudinal cross-sectional view similar to FIG. 10showing the valve during compression of the seal.

FIG. 12 is a longitudinal cross-sectional view of the fifth embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 13 is a longitudinal cross-sectional view similar to FIG. 12showing the valve during compression of the seal.

FIG. 14 is a longitudinal cross-sectional view of the sixth embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 15 is a longitudinal cross-sectional view similar to FIG. 14showing the valve during compression of the seal.

FIG. 16 is a longitudinal cross-sectional view of the seventh embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 17 is a longitudinal cross-sectional view similar to FIG. 16showing the valve during compression of the seal.

FIG. 18 is a longitudinal cross-sectional view of the eighth embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 19 is a longitudinal cross-sectional view similar to FIG. 18showing the valve during compression of the seal.

FIG. 20 is a longitudinal cross-sectional view of the ninth embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 21 is a longitudinal cross-sectional view similar to FIG. 20showing the valve during compression of the seal.

FIG. 22 is a longitudinal cross-sectional view of the tenth embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 23 is a longitudinal cross-sectional view similar to FIG. 22showing the valve during compression of the seal.

FIG. 24 is a longitudinal cross-sectional view of the eleventhembodiment of the positive-flow valve of this invention beforecompressing the seal.

FIG. 25 is a longitudinal cross-sectional view similar to FIG. 24showing the valve during compression of the seal.

FIG. 26 is a longitudinal cross-sectional view of the twelfth embodimentof the positive-flow valve of this invention before compressing theseal.

FIG. 27 is a longitudinal cross-sectional view similar to FIG. 26showing the valve during compression of the seal.

FIG. 28 is a longitudinal cross-sectional view of the thirteenthembodiment of the positive-flow valve of this invention beforecompressing the seal.

FIG. 29 is a longitudinal cross-sectional view similar to FIG. 28showing the valve during compression of the seal.

FIG. 30 is a longitudinal cross-sectional view of the fourteenthembodiment of the positive-flow valve of this invention beforecompressing the seal.

FIG. 31 is a longitudinal cross-sectional view similar to FIG. 30showing the valve during compression of the seal.

FIG. 32 is a longitudinal cross-sectional view of an alternative sealwith a side wall formed with circular tires.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The Applicant has recognized that a roller clamp may be used to induce apositive flow in a medical valve. The use of a roller clamp in a medicalvalve 190 to create a positive flow upon disconnection of a medicalimplement (not shown) is illustrated in FIG. 3. The roller-clamp valve190 is activated manually by sliding an external switch 192 to push aroller 194 against tubing 196 which connects a medical implement 198 anda catheter (not shown) to cause a positive pressure therein, therebycreating a positive flow through the catheter tip (not shown). The flowthrough the tubing 196 can be opened by sliding the switch 192 in thereverse direction.

This valve 190, however, has the same disadvantage of requiring anadditional step of operation as does the valve with a stylet illustratedin FIGS. 2a and 2 b, and also does not include a seal having a swabbablesurface. Furthermore, the size of the roller 194 must be sufficientlylarge to induce a displacement of fluid within the tube which is greaterthan the amount of fluid which may be drawn by the vacuum force (so asto generate a positive flow), which may require a bulky valve that ishard to operate.

First Embodiment

FIGS. 4 and 5 illustrate a first embodiment of a valve 210 in accordancewith the present invention. In general, this valve 210 includes a valvebody or housing 212, a support member 214, a seal 216 defining an innercavity 218, a pair of clam shells 220 a and 220 b, and a spring 222.These components are assembled, as depicted in FIG. 4, without the needfor a spike element. The inner cavity 218 forms an expandable fluidspace inside the valve 210. As discussed below, the clam shells 220a/220 b are constructed to cause the volume of the fluid space to expandor increase upon insertion of a medical implement and to contract ordecrease upon withdrawal of the medical implement.

The body or housing 212 has an upper conduit 226 near a proximal end228, desirably with a circular opening 230 that is adapted to receivethe medical implement. A side wall portion 232 is preferably tapered tocooperate with the clam shells 220 a/220 b. The body 212 has an upperledge 234 formed between the proximal end 228 and the side wall portion232. There is desirably a threaded portion on the housing 212 adjacentthe circular opening 230 in the top of the upper conduit 226, as bestseen in FIG. 4. Note that “proximal” is used to denote the end of thevalve 210 and other components at or near the body opening 230, while“distal” is used to denote the opposite end of the valve.

In the first embodiment, the upper conduit 226 is adapted to receive thetip or nose 236 of an ANSI standard syringe 238, as shown in phantom inFIG. 5. It is, however, contemplated that the outer diameter of theupper conduit 226 can be of any size to accommodate the attachment ofother connector devices thereto. Advantageously, the proximal end of theupper conduit 226 can be equipped with a locking mechanism to facilitatelocking of the valve 210 to a variety of connector devices. For example,referring to FIG. 4, the threaded portion of the housing 212 arepreferably provided such that the housing 212 can be locked into anycompatible Luer-Lock device known to those with skill in the art. Thehousing 212 of the first embodiment according to this invention includesconventional Luer-Lock threads 240 on the outer diameter of the upperconduit 226.

The support member 214 has at its distal end the inner conduit 242 whichmay be connected to a terminal end of a catheter (not shown). Thesupport member 214 serves as a support and attachment device for theseal 216 by holding the seal 216 in place inside the internal cavity 244of the housing 212. The inner conduit 242 and inner cavity 218 of theseal 216 present a continuous passageway for fluid during use.

The seal 216 is prepared from a resilient material that is flexible,inert, and impermeable to fluid, such as silicon. The seal 216 has aseal cap 248 with a generally flat top surface 250, a shoulder 252, aside wall 254, and a base 256. The side wall 254 advantageously iscomprised of wall portions 258 which deform in an accordion-like fashionand assist in the reformation of the seal 216 to close the housingopening 230 upon withdrawal of the syringe 238. During compression ofthe seal 216, the wall portions 258 expand outwardly in the radialdirection. The interior of the seal 216 is hollow to provide the innercavity 218, as best seen in FIG. 4. There are preferably gaps betweenthe wall portions 258 which facilitate deformation and reformation ofthe seal 216. The shoulder 252 engages the upper ledge 234 provided inthe upper conduit 226 of the housing 212 such that the upper ledge 234confines the movement of the shoulder 252 toward the opening 230 toprevent the seal 216 from being blown through the opening 230 under highpressure in the inner cavity 218 of the seal 216.

The seal cap 248 reseals the valve 210 at the opening 230, with the topsurface 250 of the seal 216 approximately flush with or slightly aboveor below the opening 230 upon removal of the medical implement 238.Preferably, the seal cap 248 substantially fills the opening 230 in thetop of the upper conduit 226. After assembly, the top surface 250 of theseal cap 248 is essentially flush with the opening 230, so that the sealcap 248 can be swabbed with alcohol or other disinfectant withoutleakage of the disinfectant into the valve 210. Therefore, it ispreferable that the top surface 250 be exposed so that it may be swabbedwith a disinfectant.

To provide a fluid-tight seal at the opening 230 and to eliminate theneed for a spike element to induce fluid flow upon insertion of amedical implement, the seal cap 248 has a unique shape and includes aprecut slit 259, also having a unique shape. The seal cap 248 desirablyhas an oval or elliptical shape with a major axis having a length largerthan the inner diameter of the circular opening 230 such that the ovalseal cap 248 substantially fills the opening 230 in the top of the upperconduit 226 in the decompressed state. The precut slit 259 in the sealcap 248 is squeezed shut by the circular opening 230 in the decompressedstate, as seen in FIG. 4. In its resting state, the precut slit 259 isopen. During compression of the seal 216 by insertion of a medicalimplement such as the syringe 238, as illustrated in FIG. 5, the precutslit 259 returns to its resting state and opens, as the seal cap 248 isallowed to stretch in the portion of the upper conduit 226 which has alarger inner diameter. Fluid is thus allowed to pass through the slit259. Note that the terms “compressed state” and “decompressed state” areused conveniently to refer to compression and decompression of the seal216 by insertion and withdrawal of the medical implement 238 along thelongitudinal axis of the seal 216. The terms do not relate to the radialcompression of the seal cap 248 by the opening 230 of the housing 212.

To further assist in creating a fluid-tight seal in the decompressedstate, the seal 216 of FIG. 4 advantageously includes the enlarged,internal, pressure responsive member 260 which is integral with the sealcap 248. The pressure responsive member 260 enables the valve 210 tomaintain a fluid-tight seal even at very high pressures sometimesexperienced in medical applications, particularly when the valve 210 isconnected to a patient's artery.

As shown in FIGS. 4 and 5, the clam shells 220 a/220 b are desirablyidentical pieces disposed opposite one another symmetrically inside thevalve body 212. They are preferably made of a firm material such as ahard plastic. The external surface 264 a/264 b of each clam shell 220a/220 b is tapered to cooperate with the tapered side wall portion 232of the housing 212, and is configured to slide along the side wallportion 232 during compression and decompression. The internal surfaces266 a/266 b of the clam shells 220 a/220 b cooperate with one another tosqueeze a portion of the seal side wall 254, preferably adjacent theshoulder 252, to form a constricted portion 267 of the seal 216. Theproximal ends 268 a/268 b of the clam shells 220 a/220 b engage theshoulder 252 of the seal 216 to facilitate movement of the clam shells220 a/220 b with the compression of the seal 216. The internal surfaces266 a/266 b preferably are shaped to cause the constricted portion 267to be substantially circular. In this embodiment, each internal surface266 a/266 b has a semi-circular, longitudinal groove that squeezes theseal 216.

The spring 222 is disposed between the distal ends of the clam shells220 a/220 b and the base 256 of the seal 216, but desirably a hardretaining disk 270 is provided adjacent the base 256 of the seal 216 toprovide better support for the spring 222 and the seal 216. In thedecompressed state shown in FIG. 4, the spring 222 may be relaxed or bein slight compression to exert a force on the seal 216 through the clamshells 220 a/220 b to keep the seal 216 closed. During insertion of thesyringe 238, the spring 222 is compressed and stores potential energyfrom the compression, as illustrated in FIG. 5. Upon withdrawal of thesyringe 238, the spring 222 releases the potential energy and pushes theclam shells 220 a/220 b proximally to close the seal 216, as shown inFIG. 4. The spring 222 is preferably not attached or bonded to eitherthe clam shells 220 a/220 b or the retaining disk 270 for ease ofassembly. Although FIGS. 4-5 show a helical spring 222, any suitablespring known to those of skill in the art may be used.

The seal 216 is desirably relaxed longitudinally in the decompressedstate (FIG. 4), and compressed longitudinally in the compressed state(FIG. 5). Alternatively, the seal 216 may be stretched longitudinally intension by the spring 222 in the decompressed state and be relaxed orslightly compressed longitudinal in the compressed state. The base 256of the seal 216 advantageously fits snugly and securely into a annulargroove 274 provided in the retaining disk 270 and an annular groove 276provided in the support member 214. The annular grooves 274,276 form alocking mechanism to support and secure the seal 216 within the cavity244 of the housing 212.

To illustrate valve activation, FIG. 5 shows the compressed state of thevalve 210 upon insertion of the syringe 238. A medical implement otherthan a syringe as known to those of skill in the art may be used. Thenose 236 of the syringe 238 is placed on the seal cap 248 inside theopening 230 of the housing 212. The application of pressure on thesyringe 238 creates pressure on the seal cap 248, and the resultingdownward pressure compresses the seal 216. This pushes the seal cap 248away from the circular opening 230 and toward the lower portion of thehousing cavity 244 which has a larger inner diameter, thereby allowingthe precut slit 259 to open. The downward movement is facilitated by thecompression of the spring 222 which stores the potential energy ofcompression and by the gaps between the wall portions 258 of the sidewall 254 of the seal 216. Fluid is now able to flow into the syringe238, or vice versa, depending on whether fluid is to be withdrawn fromthe patient or medication injected into the patient. FIG. 5 shows thevalve 210 opened by insertion of the nose 236 of the syringe 238 intothe opening 230. For intravenous applications, the valve 210 can beoriented in the position diagramed in FIGS. 4 and 5, or it can berotated 180′ such that fluid flows in the opposite direction.

In the compressed state shown in FIG. 5, the inner cavity 218 of theseal 216 generally contracts (becomes shorter) as compared to thedecompressed state shown in FIG. 4. The constricted portion 267 of theinner cavity 218, defined by the clam shells 220 a/220 b, however,expands (becomes larger) in volume when the seal 216 is in thecompressed state. This results from a movement of the clam shells 220a/220 b apart from one another as they slide along the tapered side wall232 of the housing 212. The amount of general contraction of the seal216 in relation to the amount of expansion of the constricted portion267 during compression determine whether the valve 210 generates apositive, negative, or zero flow upon decompression, as discussed below.

Upon removal of the syringe 238 from the upper conduit 226, as shown inFIG. 4, the seal 216 is free to move toward its decompressed state, andthe clam shells 220 a/220 b are pushed proximally toward the opening230. The movement causes a general expansion of the inner cavity 218(i.e., the cavity increases in length), but causes a contraction (i.e.,reduction in size) of the volume of the constricted portion 267 of theseal 216. If the volume change associated with the contraction of theconstricted portion 267 equals the volume change associated with theexpansion of the inner cavity 218, the fluid space or inner cavity willhave zero flow. If the increase in volume associated with the expansionof the inner cavity 218 is greater than the reduction in volumeassociated with the contraction of the constricted portion 267, therewill be a net gain in fluid space, resulting in an undesirable negativeflow toward the valve 210 through, e.g., a catheter tip (not shown). Ifthe reduction in volume associated with the contraction of theconstricted portion 267 is greater than the increase in volumeassociated with the expansion of the inner cavity 218, there will be adesirable positive flow from the valve 210 through the catheter tip (notshown). Thus, for the valve 210 to be a positive-flow valve requiresthat the clam shells be configured to allow greater expansion of theconstricted portion 267 (i.e., an increase in fluid volume in that areaof the seal 216) than the general contraction volume change associatedwith the expansion of the inner cavity 218 of the seal 216 uponcompression and, hence, greater contraction (i.e., decrease in fluidvolume within that area of the seal) of the constricted portion 267 thanthe general expansion (i.e., increase in fluid volume in that area ofthe seal) of the seal 216 upon decompression. In other words, for thevalve 210 to induce positive flow upon disconnection of the medicalimplement 238 therefrom, the total fluid volume within the valve 210must decrease. In the instant case, this decrease in fluid volume iseffectuated by causing the fluid volume within the seal to decrease asbetween its compressed (when syringe attached) and uncompressed (whensyringe detached) states. This reduction or decrease in available fluidvolume within the valve 210 causes fluid to flow towards thecatheter/patient, preventing blood from being drawn into the catheter.

That the valve 210 is advantageously configured to be a positive-flowvalve 210 eliminates any dead space during decompression of the seal 210as the syringe 238 is withdrawn, as illustrated in FIG. 4. Furthermore,as the syringe 238 is withdrawn, the slit 259 remains open until thevery end, i.e., until the seal cap 248 is squeezed by the circularopening 230 at the top of the upper conduit 226. This further assists ineliminating dead space and avoiding backflash. This feature isparticularly advantageous in the case where the valve 210 is connectedthrough a catheter to a patient, because it prevents blood from beingdrawn into the catheter and clogging it. This invention thereforeeliminates a significant risk by solving the problem of backflash.

As the seal 216 is free to move to its decompressed state, itessentially fills the opening 230. The ability of the seal 216 to returnto its original shape and be deformed in its decompressed state isdetermined by the resiliency of the material used to prepare the seal216. Advantageously, the ability of the seal 216 to return to itsdecompressed state is facilitated by the spring 222 and the gaps betweenthe wall portions 258 of the seal 216. The ability of the seal 216 todeform reversibly and return to its decompressed state is particularlyuseful because (1) it immediately stops fluid flow through the valve210, and (2) it maintains sterility of the valve.

The ability of the seal 216 to return reversibly to its decompressedstate permits reuse of the valve 210. Following disconnection, andbefore reuse, the surface 250 of the seal cap 248 is essentially flushwith the opening 230 of the housing 212. Thus, this flush surface 250can advantageously be sterilized with alcohol or othersurface-decontaminating substances. The support member 214 and body 212advantageously shield both connections from the surrounding environmentto protect the sterility of the connection.

A cover cap (not shown) can be supplied to fit over the upper conduit226 as further protection for the surface 250 of the seal cap 248 whennot in use. Such a cover cap, however, is not needed to maintainsterility since the seal 216 may be swabbed with a disinfectant beforeand/or after each use. Reversibility of the seal 216 makes the valve 210particularly attractive as a connector valve to provide fluidcommunication between two fluid lines. Therefore, the present inventionprovides for placing a first fluid line in communication with a secondfluid line using the valve 210 disclosed herein. The reversibility ofthe valve 210 permits multiple fluid lines to be successively added, forexample, to a fluid line in direct communication with a patient's vein.Since the valve 210 is easily sterilized and sealable, fluid lines canbe added and removed without disconnecting venous contact of thecatheter.

The valve body 212 and support member 214 are preferably prepared from ahard plastic, but it is additionally contemplated that the valve 210could be prepared from other medically inert materials known to thoseskilled in the art. Another feature of this invention is that it reliesneither on a needle nor on a spike in order to establish fluid flowthrough the valve. This completely eliminates the risk of skin punctureor fear of puncture during use and manufacture. It also eliminatescoring of the seal 216 by a spike element and all the risks associatedtherewith. Further, the fluid flow rate is not limited by the size of athrough passage in a needle or spike, as is the case in some prior artvalves.

As shown in FIG. 4, another feature of the invention is that the upperledge 234 confines the movement of the shoulder 252 toward the opening250 to prevent the seal 216 from being blown through the opening 230under high pressure in the cavity 218. This makes the valve 210particularly suited for high pressure applications.

Second Embodiment

In a second embodiment of the present invention illustrated in FIGS. 6and 7, the valve 310 includes a valve body or housing 312, a supportmember 314, a skirt 316, a seal 318, a resilient member 320, and a pairof clam shells 322 a/322 b. The housing 312 is desirably similar to thehousing 212 of FIG. 4 and has a tapered side wall 324.

Referring to FIGS. 6 and 7, the second embodiment of the valve 310 has abell-shaped skirt 316. The skirt 316 has an annular ring 328 which isdisposed toward an inner conduit 330 of the support member 314. Theskirt 316 creates a shield for the inner conduit 330. This inner conduit330 is preferably cylindrical in shape and slightly tapered. The innerconduit may be connected to a terminal end of a catheter (not shown),which has an opposite, open end that is generally inserted into apatient. The support member 314 serves as a support and attachmentdevice for the seal 318 by holding the seal 318 in place inside thehousing 312.

The support member 314 also serves as a support and attachment devicefor the skirt 316. As best seen in FIG. 6, the support member 314 has anedge portion 332 which engages a ledge 334 of the skirt 316 in assembly.This attachment secures the skirt 316 in place. The skirt 316 desirablyincludes a Luer-Lock portion 336 that enables the valve 310 to beremovably attached to, for example, a fluid line or catheter connectedto a patient. It is noted that the valve 310 in this embodiment includesa skirt 316 separate from the housing 312 for ease of assembly. Adifferent embodiment can provide a unitary member which replaces thehousing 312 and skirt 316. It is therefore contemplated that such anembodiment would fall within the scope of this invention.

The seal 318 is similar to the seal 210 of FIG. 4. The seal 318 is alsopreferably silicon and has a similar seal cap 340 with a precut slit342, shoulder 344, and pressure responsive member 348. These componentsserve the same function as those of the seal 210. Instead of a side wallformed with wall portions 258, the seal 318 has a side wall 350 that isgenerally circular cylindrical and has a distal portion 352 that issized to be slip-fitted with the proximal end 354 of the inner conduit330 of the support member 314. During compression of the seal 318, theside wall 350 simply slides over the proximal end 354 of the innerconduit 330, forming a fluid-tight seal therewith. The seal 318 definesan inner cavity 358 above the proximal end 354 of the inner conduit 330.The inner cavity 358 forms an expandable fluid space inside the valve310. The inner conduit 330 and inner cavity 358 comprise aligned hollowtubes in fluid communication with each other when the precut slit 342 ofthe seal 318 opens during compression of the seal 310.

Similar in form and function to the clam shells 220 a/220 b of FIGS. 4and 5, the clam shells 322 a/322 b are constructed to cause an increasein fluid space upon insertion of a medical implement into the valve 310and a decrease in fluid space upon withdrawal of the medical implementsuch as a syringe 362 partially shown in phantom in FIG. 7. The internalsurfaces 364 a/364 b of the clam shells desirably have longitudinalgrooves that cooperate with one another to squeeze a portion of the sealside wall 350 to form a constricted portion 366 thereof.

Instead of the spring 222 in FIG. 4, the second embodiment employs theresilient member 320 disposed between the clam shells 322 a/322 b andthe support member 314. The resilient member 320 advantageously is inertand impermeable to fluid such as silicon, and includes wall portions 368which deform in an accordion-like fashion and assist in the reformationof the seal 318 to close the housing opening 370 upon withdrawal of thesyringe 362. The resilient member 320 thus is similar in constructionwith and serves the same function as the spring 222 of the seal 210 ofFIGS. 4 and 5. It is contemplated that a spring (not shown) similar tothe spring 222 of FIG. 4 may be used in place of the resilient member320, as may other suitable structures known to those of skill in theart.

As shown in FIGS. 6 and 7, the resilient member 320 has a base 346. Thebase 346 fits snugly and securely within an annular groove 374 providedin the housing 312 and an annular groove 377 provided in the supportmember 314, as shown in FIG. 6. The annular grooves 376,377 hence form alocking mechanism to support and secure the resilient member 320 withinthe housing 312. The shoulder 344 engages an upper ledge 382 provided inan upper conduit 384 of the housing 312 such that the upper ledge 382confines the movement of the shoulder 344 toward the opening 370 toprevent the seal 318 from being blown through the opening 370 under highpressure in the inner cavity 358 of the seal 318.

The resilient member 320 is desirably relaxed or slightly compressedlongitudinally in the decompressed state (FIG. 6), and compressedlongitudinally in the compressed state (FIG. 7). The resilient member320 is desirably not attached or bonded to either of the clam shells 322a/322 b or the housing 312.

FIG. 7 illustrates compression and FIG. 6 illustrates decompressionduring valve activation. In the compressed state, the syringe 362 isplaced on the seal cap 340 inside the opening 370 of the housing 312,and the application of pressure on the syringe 362 creates pressure onthe seal cap 340. The downward pressure pushes the seal cap 340 awayfrom the circular opening 370 and toward the distal lower portion of thehousing 312 which has a larger inner diameter, thereby allowing theprecut slit 342 to open. The side wall 350 slides over the proximal end354 of the inner conduit 330, and the resilient member 320 deforms in anaccordion-like manner, storing potential energy of the compression.Fluid is able to flow into the syringe 362, or vice versa, depending onwhether fluid is to be withdrawn from the patient or medication injectedinto the patient.

The compression of the seal 318 shown in FIG. 7 generally causes acontraction or reduction in the volume of the inner cavity 358 of theseal 318. The valve 310 has a net gain in volume of the inner cavity318, however, because the general reduction in volume within the innercavity 358 is less than an increase in volume within the constrictedportion 366 of the inner cavity 358 defined by the clam shells 322 a/322b. The expansion results from the movement of the clam shells 322 a/322b apart from one another during compression, facilitated by the taperedside wall 324 of the housing 312.

FIG. 6 illustrates the valve after withdrawal of the syringe 362. Theseal 318 returns to its decompressed state and essentially fills theopening 370, and the clam shells 322 a/322 b are pushed proximallytoward the opening 370 by the resilient member 320. Because of thecontraction of the inner cavity 358 at the constricted portion 366 bythe clam shells 322 a/322 b, there is a net loss or reduction in fluidspace, resulting in a positive flow from the valve 310 through, e.g., acatheter tip (not shown). The positive-flow valve 310 advantageouslyeliminates any dead space during decompression of the seal 318. This isfurther assisted by the seal 318 with the slit 342 remaining open untilthe very end, i.e., until the seal cap 340 is squeezed by the upperconduit 384.

In addition, the valve 310 can be reused because the seal 318 can returnreversibly in the decompressed state. The seal surface 340 is alsoswabbable for sterility. Other features of the valve 310 are discussedpreviously in connection with the first embodiment of this invention andwill not be repeated.

Third Embodiment

As shown in FIGS. 8 and 9, a third embodiment of the valve 410 of thepresent invention comprises a valve body or housing 412, a supportmember 414, a flexible tubing 416, a seal 418, a ring member 420, a pairof clam shells 422 a/422 b, and a spring 424. The flexible tubing 416may be connected to a catheter (not shown) and, together with the seal418, defines an inner cavity 426. The inner cavity 426 forms anexpandable fluid space of the valve 410. The clam shells 422 a/422 bdesirably are substantially the same as the clam shells 220 a/220 b ofFIG. 4 and are constructed to cause the fluid space within the valve 410to increase upon insertion of a medical implement and to decrease uponwithdrawal of the medical implement such as a syringe 428 partiallyshown in phantom in FIG. 9. The housing 412 is desirably similar to thehousing 212 of FIG. 4.

The support member 414 has a hollow center 430 which supports theflexible tubing, and a proximal end 432 which encloses a distal end 434of the housing 412. The support member 414 desirably locks onto thehousing 412 via any method known to those of skill in the art. Theproximal end 432 of the support member 414 supports the spring 424,which in turn supports the clam shells 422 a/422 b and seal 418.

The seal 418 is prepared from a resilient material that is flexible,inert, and impermeable to fluid, such as silicon. Referring to FIG. 8,the seal 418 is substantially similar to the seal 210 of FIG. 4, with aportion of the side wall 438 cut off near the shoulder 440 region. As aresult, the side wall 438 of the seal 418 is substantially shorter thanthe side wall 254 of the seal 210 in FIG. 4. A distal end 442 of theside wall 254 is attached, preferably by adhesive, to a proximal end 444of the flexible tubing 416. The distal end 442 abuts the ring member 420which is disposed between the seal 418 and the clam shells 422 a/422 band attached at its inner surface 446 to a portion of the tubing 416,desirably also by adhesive. Other suitable means of attachment may beused. The ring member 420 is desirably made of polycarbon.

The clam shells 422 a/422 b desirably form a sliding contact at theirproximal ends with the ring member 420 for ease of assembly, but mayalternatively be affixed to the ring member 420 by adhesive or similarmeans. The clam shells 422 a/422 b are desirably the same as the clamshells 220 a/220 b of FIG. 4, having tapered external surfaces 450 a/450b to cooperate with the tapered side wall portion 452 of the housing 412for sliding and grooved internal surfaces 454 a/454 b that cooperatewith one another to squeeze a portion of the tubing 416 to form aconstricted portion 456.

The spring 424 is substantially the same as the spring 222 of FIG. 4 andserves the same function, being disposed between the distal ends of theclam shells 422 a/422 b and the proximal end 432 of the support member414. In the decompressed state shown in FIG. 8, the spring 424 may berelaxed or in slight compression to exert a force on the seal 418through the clam shells 422 a/422 b to keep the slit 466 in the seal cap460 closed. During insertion of the syringe 428, the spring 424 iscompressed and stores potential energy from the compression, asillustrated in FIG. 9. Upon withdrawal of the syringe 428, the spring424 releases the potential energy and pushes the clam shells 422 a/422 bproximally to close the seal 418, as shown in FIG. 8. The spring 424 ispreferably not attached or bonded to either the clam shells 422 a/422 bor the support member 414 for ease of assembly. The spring 424 can be ahelical spring or any other suitable spring known to those with skill inthe art.

FIG. 9 shows the compressed state of the valve 410 upon insertion of thesyringe 428. In the compressed state, the syringe 428 is placed on theseal cap 460 inside the opening 464 of the housing 412 and theapplication of pressure on the syringe 428 creates pressure on the sealcap 460. The downward pressure pushes the seal cap 460 away from thecircular opening 464 and toward the distal end of the housing 412, whichhas a larger inner diameter, thereby allowing the precut slit 466 of theseal cap 460 to open. The resilient tubing 416 and the clam shells 422a/422 b also move distally as the spring 424 deforms in compression,storing potential energy. Fluid is able to flow into the syringe 428, orvice versa, depending on whether fluid is to be withdrawn from thepatient or medication injected into the patient.

The compression of the seal 418 shown in FIG. 9 generally causes areduction in the volume of the inner cavity 426 formed by the seal 418and tubing 416. However, because of an expansion of the constrictedportion 456 defined by the clam shells 422 a/422 b an increase in fluidvolume is created which is greater than the general reduction in fluidvolume within the inner cavity 426, the valve 410 has a net gain influid volume. The increase in fluid volume results from the movement ofthe clam shells 422 a/422 b apart from one another during sealcompression, facilitated by the tapered side wall 452 of the housing 412and resiliency of the tubing 416.

FIG. 8 illustrates the valve 410 after withdrawal of the syringe 428.The seal 418 returns to its decompressed state and essentially fills theopening 464, and the clam shells 422 a/422 b are pushed proximallytoward the opening 464 by the spring 424. Because of the contraction ofthe inner cavity 426 at the constricted portion 456 by the clam shells422 a/422 b, there is a net loss in fluid space, resulting in a positiveflow from the valve 410 through, e.g., a catheter tip (not shown). Thepositive-flow valve 410 advantageously eliminates any dead space duringdecompression of the seal 418. This is further assisted by the seal 418,with the slit 466 remaining open until the very end, i.e., until theseal cap 460 is squeezed by upper conduit 470.

In addition, the valve 410 can be reused because the seal 418 can returnreversibly in the decompressed state. The seal surface 472 is alsoswabbable for sterility. Other features of the valve 410 are discussedpreviously in connection with the earlier embodiments of this inventionand will not be repeated.

Fourth Embodiment

A fourth embodiment of the present invention is illustrated in FIGS. 10and 11. As illustrated therein, a valve 510, comprises a valve body orhousing 512, a support member 514, a skirt 516, a retaining member 518,a seal 520, a pair of clam shells 522 a/522 b, and a resilient member524. The valve 510 has several features that are the same or similar tothose of the valve 310 of FIGS. 8 and 9, having a similar resilientmember 524 and clam shells 522 a/522 b. The clam shells 522 a/522 b haveinternal surfaces 526 a/526 b that cooperate with one another to squeezea portion of the seal side wall 528 to form a constricted portion 530thereof.

The seal 510 is preferably made of silicon and has a seal cap 532 with aprecut slit 534, shoulder 536, lower lip 538, and pressure responsivemember 540 that are similar to the seal 210 of FIG. 4. These componentsserve the same function as those of the seal 210. The side wall 528 maybe formed with ringed wall portions 258, as in the seal 210, but FIG. 4shows the side wall 528 that is generally circular cylindrical. The seal520 defines an inner cavity 542 which forms an expandable fluid spaceinside the valve 510. During compression of the seal 520, the side wall528 deforms outwardly into a circumferential cusp or bulge 544 in theunconstricted region between the clam shells 522 a/522 b and the supportmember 514. The side wall 528 returns to its decompressed shape upondecompression of the seal 520. The seal 520 is desirably relaxedlongitudinally in the decompressed state (FIG. 10), and compressedlongitudinally in the compressed state (FIG. 11). Alternatively, theseal 520 may be stretched longitudinally in tension by the resilientmember 524 in the decompressed state and be relaxed or slightlycompressed longitudinal in the compressed state.

Referring to FIG. 10, the skirt 516 is a bell-shaped skirt that issimilar to the skirt 316 of FIG. 8. The skirt 516 creates a shield foran inner conduit 548 of the support member 514. The inner conduit 548may be connected to a terminal end of a catheter (not shown) which hasan open end that is generally inserted into a patient. The supportmember 514 serves as a support and attachment device for the seal 520 byholding the seal 520 in place inside the housing 512.

The support member 514 also serves as a support and attachment devicefor the skirt 516. Similar to the valve 310 of FIG. 8, the supportmember 514 shown in FIG. 10 has an edge portion 550 which engages aledge 552 of the skirt 516 in assembly. This attachment secures theskirt 516 in place. The skirt 516 desirably includes a Luer-Lock portion554 that enables the valve 510 to be removably attached to, for example,a fluid line or catheter connected to a patient.

The retaining member 518 is desirably provided to secure the lower lip538 of the seal 520 and support the resilient member 524. The retainingmember 518 is held inside the housing 512 by the support member 514, andis provided for ease of assembling the valve 510. The retaining member518 has an annular groove 556, and the support member 514 has an annulargroove 558. The annular grooves 556,558 form a locking mechanism tosupport and secure the seal 520 within the housing 512 by engaging thelower lip 538 snugly with the grooves 556,558. It is noted that adifferent embodiment may provide a unitary member which replaces thesupport member 514 and the retaining member 518. It is thereforecontemplated that such an embodiment would fall within the scope of thisinvention.

FIG. 11 illustrates compression and FIG. 10 illustrates decompressionduring valve activation. In the compressed state, a medical implementsuch as the syringe 562 partially shown in phantom is placed on the sealcap 532 inside the opening 564 of the housing 512, and the applicationof pressure on the syringe 562 creates pressure on the seal cap 532. Thedownward pressure pushes the seal cap 532 away from the circular opening564 and toward the lower portion of the housing 512, which has a largerinner diameter, thereby allowing the precut slit 534 to open. The sidewall 528 deforms outwardly at the unconstricted region into acircumferential cusp 544, and the resilient member 524 deforms in anaccordion-like manner, storing potential energy of the compression.Fluid is able to flow into the syringe 562, or vice versa, depending onwhether fluid is to be withdrawn from the patient or medication injectedinto the patient.

The compression of the seal 520 shown in FIG. 11 generally causes areduction in the fluid volume of the inner cavity 542 of the seal 520.The valve 510 has a net gain in volume of the inner cavity 542, however,because the general reduction in volume within the inner cavity 542 isless than the increase in volume within the constricted portion 530 asdefined by the clam shells 522 a/522 b and of the cusp 544 at theunconstricted region of the seal 520.

FIG. 10 illustrates the valve 510 after withdrawal of the syringe 562.The seal 520 returns to its decompressed state and essentially fills theopening 564, and the clam shells 522 a/522 b are pushed back up towardthe opening 564 by the resilient member 524. Because of the contractionof the inner cavity 542 of the seal 520, there is a net loss in fluidspace, resulting in a positive flow from the valve 510 through, e.g., acatheter tip (not shown). The positive-flow valve 510 advantageouslyeliminates any dead space during decompression of the seal 520. This isfurther assisted by the seal 520, with the slit 534 remaining open untilthe very end, i.e., until the seal cap 532 is squeezed by the circularopening 564 at the top of the upper conduit 570.

In addition, the valve 510 can be reused because the seal 520 can returnreversibly in the decompressed state. The seal surface 572 is alsoswabbable for sterility. Other features of the valve 510 are discussedpreviously in connection with the earlier embodiments of this invention.

Fifth Embodiment

FIGS. 12 and 13 show a fifth embodiment valve 610 in accordance with thepresent invention, the valve 610 comprising a valve body or housing 612,a seal 614, a ring member 616, and a spring 618. The housing 612 issimilar to the housing 212 of FIG. 4, with a circular opening 620, and atapered side wall 622, but may have a straight side wall instead. Theseal 614 is similar to the seal 318 of FIG. 8, having a substantiallycylindrical side wall 624 and defining an inner cavity 626 which formsan expandable fluid space inside the valve 610. The side wall 624 mayhave different and variable thickness (not shown). The components aredimensioned and configured to cause the fluid space to expand uponinsertion of a medical implement and to contract upon withdrawal of themedical implement such as a syringe 630 partially shown in phantom inFIG. 13. The distal portion of the seal 614 is connected to a fluid linesuch as a catheter (not shown), and may be secured to the housing bymeans known to those with skill in the art, such as by the use of asupport member (not shown) similar to the support member 214 shown inFIG. 15.

The ring member 616 is desirably an annular disk 616 made of a hardplastic and disposed between a shoulder 634 of the seal 614 and aproximal end 636 of the spring 618. The ring member 616 serves as aconstraint for the seal 614 during compression and efficiently transfersthe compressive force to the spring 618, assisting in the deformation ofthe seal 614. During decompression, the ring member 616 efficientlytransfers the spring force to the seal cap 638 of the seal 614 to closethe opening 620. Although the ring member 616 facilitates thedeformation and reformation of the seal 614, it is not necessary for theseal 614 to work. In that case, the spring 618 will contact the seal cap638 directly.

The spring 618 is substantially the same as the spring 222 of FIG. 4 andserves the same function, being disposed between the ring member 616 anda distal end 642 of the housing 612. In an alternative embodiment, thedistal end 642 may be a separate component from the housing 612 for easeof assembly. In the decompressed state shown in FIG. 12, the spring 618may be relaxed or be in slight compression to exert a force on the seal614 through the ring member 616 to keep the seal 614 closed. Duringinsertion of the syringe 630, the spring 618 is compressed and storespotential energy from the compression, as illustrated in FIG. 13. Uponwithdrawal of the syringe 630, the spring 618 releases the potentialenergy and pushes the ring member 616 to close the seal 616 as shown inFIG. 12. The spring 618 is preferably not fixed with either the ringmember 616 or the distal end 642 of the housing 612 for ease ofassembly. The spring 618 can be a helical spring or any other suitablespring known to those with skill in the art.

The side wall 624 of the seal 614 is constrained by the ring member 616and housing 612, and is substantially relaxed in the decompressed state.During compression of the seal 614, the side wall 624 bulges in theunconstrained region between the ring member 616 and the distal end 642of the housing 612, causing an increase in the fluid space within thevalve 610. The side wall 624 returns to its decompressed shape upondecompression of the seal 614. Alternatively, the side wall 624 may bestretched in tension by the spring 618 in the decompressed state andgoes through a relaxed position before deforming under compression toits bulged condition.

FIG. 13 illustrates compression and FIG. 12 illustrates decompressionduring valve activation. In the compressed state, the syringe 630 isplaced on the seal cap 638 inside the opening 620 of the housing and theapplication of pressure on the syringe 630 creates pressure on the sealcap 638. The downward pressure pushes the seal cap 638 and the ringmember 616 away from the circular opening 620 and toward the lowerportion of the housing 612 which has a larger inner diameter, therebyallowing the precut slit 646 of the seal cap 638 to open. The side wall624 deforms outwardly and bulges at the unconstricted region, as thespring 618 is compressed, storing potential energy of the compression.Fluid is able to flow into the syringe 630, or vice versa, depending onwhether fluid is to be withdrawn from the patient or medication injectedinto the patient. The compression of the seal 614 shown in FIG. 13results in a net gain in volume of the inner cavity.

FIG. 12 illustrates the valve 610 after withdrawal of the syringe 630.The seal 614 returns to its decompressed state and essentially fills theopening 620, and the ring member 616 is pushed back up toward theopening 620 as the spring 618 releases its potential energy. Because ofthe contraction of the inner cavity 626 of the seal 614, there is a netloss in fluid space, resulting in a positive flow from the valve 610through, e.g., a catheter tip (not shown). The positive-flow valve 610advantageously eliminates any dead space during decompression of theseal 614. This is further assisted by the seal 614 with the slit 646remaining open until the very end, i.e., until the seal cap 638 issqueezed by the circular opening 620 at the top of the upper conduit 650of the housing 612.

In addition, the valve 610 can be reused because the seal 614 can returnreversibly in the decompressed state. The seal surface 652 is alsoswabbable for sterility. Other features of the valve 610 are discussedpreviously in connection with the earlier embodiments of this invention.

Sixth Embodiment

A sixth embodiment of a valve 710 is illustrated in FIGS. 14 and 15. Thevalve 710 comprises a valve body or housing 712 and a seal 714. Thehousing 712 has an upper conduit 716 near a proximal end with a circularopening 718 that is preferably adapted to receive a medical implement. Aside wall portion 720 is protruded to facilitate deformation of the seal714. A distal end 724 of the housing 712 forms a lower passage 726(partially shown) which supports and constrains a distal portion 728 ofthe seal 714, and is connected, for example, to a fluid line such as acatheter (not shown). Alternatively, a support member (not shown) may beused to detachably lock onto the housing 712 and support the seal 714,such as those shown in FIG. 4 (214) or FIG. 12 (514).

The seal 714 is generally similar to the seal 614 of FIGS. 12 and 13,and has a substantially cylindrical side wall 721, although the sidewall 732 may have a slight bulge 733 as shown in FIG. 14. It defines aninner cavity 734 which forms an expandable fluid space inside the valve710. In the decompressed state, the seal 714 is constrained by the upperconduit 716 and lower passage 726 of the housing 712, and issubstantially relaxed in the decompressed state. The components aredimensioned and configured to cause the fluid space to expand orincrease upon insertion of the medical implement and to contract ordecrease upon withdrawal of the medical implement such as the syringe730 partially shown in phantom in FIG. 15. During compression of theseal 714, the side wall 732 bulge in the unconstrained region betweenthe upper conduit 716 and lower passage 726 and the bulge 738 issubstantially round. The side wall 732 return to its decompressed shapeupon decompression of the seal 714.

FIG. 15 illustrates compression and FIG. 14 illustrates decompressionduring valve activation. In the compressed state, the syringe 730 isplaced on the seal cap 742 of the seal 714 inside the opening 718 of thehousing 712 and the application of pressure on the syringe 730 createspressure on the seal cap 742. The downward pressure pushes the seal cap742 away from the circular opening 718 and toward the protruded portion720 of the housing 712 which has a larger inner diameter, therebyallowing the precut slit 746 of the seal cap 742 to open. The side wall732 deforms outwardly and bulges at the unconstricted region 738,storing potential energy of the compression. Fluid is able to flow intothe syringe 730, or vice versa, depending on whether fluid is to bewithdrawn from the patient or medication injected into the patient. Thecompression of the seal 714 shown in FIG. 15 generates a net gain involume of the inner cavity.

FIG. 14 illustrates the valve 710 after withdrawal of the syringe 730.The seal 714 returns to its decompressed state and essentially fills theopening 718. Because of the contraction of the inner cavity 734 of theseal, there is a net loss in fluid space, resulting in a positive flowfrom the valve 710 through, e.g., a catheter tip (not shown). Thepositive-flow valve 710 advantageously eliminates any dead space duringdecompression of the seal 714. This is further assisted by the seal 714with the slit 746 remaining open until the very end, i.e., until theseal cap 742 is squeezed by the circular opening 718 at the top of theupper conduit 716.

In addition, the valve 710 can be reused because the seal 710 can returnreversibly in the decompressed state. The seal surface 748 is alsoswabbable for sterility. Other features of the valve 710 are discussedpreviously in connection with the earlier embodiments of this invention.

Seventh Embodiment

FIGS. 16 and 17 illustrate a valve 710 in accordance with a seventhembodiment of the present invention, the valve 756 comprising a valvebody or housing 758 and a seal 760 that are substantially the same asthe housing 712 and seal 714 of FIGS. 14 and 15, with a distal portion762 of the seal 760 connected to a fluid line such as a catheter (notshown). The seal 760, however, is configured to deform upon compressioninto a diamond-shaped cusp 764 instead of a round bulge 738 asillustrated in FIGS. 14 and 15. This type of construction may facilitatedeformation and reformation of the seal 760, and may be more easilyformed. The valve activation of this embodiment is virtually identicalto that in FIGS. 14 and 15, except for the deformed shape of the sealside wall 770. It is contemplated, therefore, that a seal that maydeform into a variety of shapes other than round and diamond shapes toachieve positive flow may be employed, as long as the it is dimensionedand configured to cause the fluid space of the valve to expand uponinsertion of a medical implement and to contract upon withdrawal of themedical implement such as the syringe 774 partially shown in phantom inFIG. 28.

Eighth Embodiment

As illustrated in FIGS. 18 and 19, an eighth embodiment valve 810 of thepresent invention is similar to the embodiments shown in FIGS. 14-17.The valve 810 also includes a housing 812 having an internal cavity 814with an upper conduit 816, and a seal 818 disposed inside the internalcavity 814 and having an inner cavity 820 that defines a fluid space.The housing 812 has a distal end 824 which supports a side wall 826 ofthe seal 818. A distal portion 828 of the seal 818 is connected to afluid line such as a catheter (not shown). The pressure at the innercavity 820 of the seal 818 is P1. Between the housing 812 and the seal818 is an enclosed pressure chamber 832 at pressure P2. The valveactivation utilizes the pressure difference between P2 in the pressurechamber 832 and P1 in the inner cavity 820 of the seal 818.

Upon insertion of a medical implement such as a syringe 836 shown inphantom in FIG. 19, the pressure at the inner cavity 820 of the seal 818increases from P1 to P3 and the fluid space inside the seal 818 expandsfrom the decompressed state of FIG. 18. The expansion of the fluid spaceresults primarily from a difference in pressure between P3 and P2. Thisvalve 810 is particularly advantageous in the case where the side wall826 of the seal 818 deforms without storing substantial potentialenergy. For instance, the side wall 826 of the seal 818 may deformwithout substantial resistance or resiliency such as a membrane, or theseal is not constrained longitudinal by the distal portion 824 of thehousing 812 and may slide in and out of the internal cavity 814 of thehousing 812 through the distal end 824.

FIG. 19 illustrates compression and FIG. 18 illustrates decompressionduring valve activation. In the compressed state, the syringe 836 isplaced on the seal cap 838 of the seal 818 inside the opening 840 of thehousing 812 and the application of pressure on the syringe createspressure on the seal cap 838. The downward pressure pushes the seal cap838 away from the circular opening 840 and toward the lower portion ofthe housing 812 which has a larger inner diameter, thereby allowing theprecut slit 844 of the seal cap 838 to open. The entry of the fluidcauses the pressure at the inner cavity 814 of the seal 812 to increaseto P3. As a result, the side wall 826 deforms outwardly and bulges atthe unconstricted region 848. Potential energy is stored in the changein pressure differential between the inner cavity 820 and the pressurechamber 832. The side wall 826 of the seal 818 need not deform and storeenergy, but may do so. Fluid is able to flow into the syringe 836, orvice versa, depending on whether fluid is to be withdrawn from thepatient or medication injected into the patient. The compression of theseal 818 shown in FIG. 19 causes a net gain or increase in fluid volumewithin the inner cavity.

FIG. 18 illustrates the valve 810 after withdrawal of the syringe 836.The seal 818 returns to its decompressed state and essentially fills theopening 840, and the pressure in the inner cavity 820 returns to P1 andreleases the potential energy. Because of the contraction of the innercavity 820 of the seal 818, there is a net loss in fluid space,resulting in a positive flow from the valve 810 through, e.g., acatheter tip (not shown). The positive-flow valve 810 advantageouslyeliminates any dead space during decompression of the seal 818. This isfurther assisted by the seal 818 with the slit 844 remaining open untilthe very end, i.e., until the seal cap 838 is squeezed by the circularopening 840 at the top of the upper conduit 816.

In addition, the valve 810 can be reused because the seal 818 can returnreversibly in the decompressed state. The seal surface 854 is alsoswabbable for sterility. Other features of the valve 810 are discussedpreviously in connection with the earlier embodiments of this invention.

Ninth Embodiment

A ninth embodiment of a valve 910 comprising a housing 912, a supportmember 914, a skirt 916, a seal 918, and a scissor-like cross member920, is depicted in FIGS. 20 and 21. The housing 912 has an upperconduit 924 with a circular opening 926. The support member 914 has aninner conduit 928 which is connected to a fluid line such as a catheter(not shown). The seal 918 has a side wall 930 desirably formed ofalternating wall portions 932 and defines an inner cavity 934 whichforms an expandable fluid space inside the valve 910. The cross member920 is dimensioned and configured to assist in causing the fluid spaceto expand upon insertion of a medical implement and to contract uponwithdrawal of the medical implement such as the syringe 936 partiallyshown in phantom in FIG. 21.

The cross member 920 has two longitudinal member 940 attached togetherwhich rotates with respect to one another, and is desirably made of ahard material such as a hard plastic. The cross member 920 is disposedat a constricted portion 942 of the seal 918 within the inner cavity 934with the longitudinal members 940 preferably substantially disposedvertically. The ends 944 of the longitudinal members 940 are desirablyattached to the side wall 930 as shown in FIG. 20. The longitudinalmembers 940 rotate to a substantially horizontal orientation uponcompression by the insertion of the syringe 936 as shown in FIG. 21.This rotation is referred to as the deformation of the cross member 920.The longitudinal members 940 may be attached to rotate freely withrespect to one another. Alternatively, the longitudinal members 940 maybe spring-loaded or attached such that they rotate under a rotationalforce but reform to their relaxed position upon release of the force.Upon withdrawal of the syringe 936 as shown in FIG. 20, the longitudinalmembers 940 return to the substantially vertical positions, referred toas the reformation of the cross member 920. The longitudinal members 940are desirably longitudinal plates 940 with sufficient width to expandthe constricted portion 942 of the seal 918 in the substantiallyhorizontal position but not so wide that they impedes flow therethrough.Alternatively, they may contain holes (not shown) through which fluidcan pass.

FIG. 21 illustrates compression and FIG. 20 illustrates decompressionduring valve activation. In the compressed state, the syringe 926 isplaced on the seal cap 950 of the seal 918 inside the opening 926 of thehousing 912 and the application of pressure on the syringe 936 createspressure on the seal cap 950. The downward pressure pushes the seal cap950 away from the circular opening 926 and toward the lower portion ofthe housing 912 which has a larger inner diameter, thereby allowing theprecut slit 952 of seal cap 950 to open. The side wall 930 of the seal918 deforms in an accordion-like manner, and the cross member 920deforms and opens up the constricted portion 922 of the seal 918,storing potential energy of the compression. Fluid is able to flow intothe syringe 936, or vice versa, depending on whether fluid is to bewithdrawn from the patient or medication injected into the patient. Thecompression of the seal 918 and deformation of the cross 920 shown inFIG. 21 generally causes a contraction of the volume of the inner cavity934 of the seal 918. The valve 910 has a net gain in volume of the innercavity 934, however, because the general contraction of the inner cavity934 is less than by the expansion of the constricted portion 942 pushedapart by the cross member 920. The expansion results from the movementof the longitudinal members 940 of the cross member 920 duringcompression.

FIG. 20 illustrates the valve 910 after withdrawal of the syringe 936.The seal 918 returns to its decompressed state and essentially fills theopening 926, and the cross member 920 reforms to allow the constrictedregion 942 of the seal 918 to narrow. Because of the contraction of theinner cavity 934 at the constricted portion 942, there is a net loss influid space, resulting in a positive flow from the valve 910 through,e.g., a catheter tip (not shown). The positive-flow valve 910advantageously eliminates any dead space during decompression of theseal 918. This is further assisted by the seal 918 with the slit 952remaining open until the very end, i.e., until the seal cap 950 issqueezed by the circular opening 926 at the top of the upper conduit924.

In addition, the valve 910 can be reused because the seal 918 can returnreversibly in the decompressed state. The seal surface 960 is alsoswabbable for sterility. Other features of the valve 910 are discussedpreviously in connection with the earlier embodiments of this invention.

Tenth Embodiment

FIGS. 22 and 23 illustrate a valve 1010 in accordance with a tenthembodiment of the present invention, the valve 1010 comprising a valvebody or housing 1012, a support member 1014 (partially shown), a seal1016, a ring member 1018, a resilient reel 1020, and a scissor-likecross member 1022. The support member 1014 has an inner conduit (notshown) which is connected to a fluid line such as a catheter (notshown). The seal 1016 has a seal cap 1028 with slit 1030, shoulder 1032,and pressure responsive member 1034.

The ring member 1018 forms a sliding contact with a distal end 1036 ofthe seal 1016 and is preferably made from a hard plastic. The ringmember 1018 desirably has a shoulder 1038 which is constrained by aledge 1040 of the housing 1012 in the upward direction. The distal endof the ring member 1018 contacts an upper flange 1044 of the resilientreel 1020 and facilitates transfer of the compressive force due toinsertion of a medical implement to cause deformation of the reel 1020.The reel 1020 is made from a material that is flexible, inert, andimpermeable to fluid, such as silicon. It has a lower flange 1046 thatis supported and secured by the support member 1014 and a central bodyportion 1048 that is substantially cylindrical. The seal 1016, ringmember 1018, and resilient reel 1020 define an inner cavity 1050 whichforms an expandable fluid space inside the valve 1010.

The cross member 1022 is substantially the same of the cross member 920of FIGS. 20 and 21 and is dimensioned and configured to assist incausing the fluid space to increase upon insertion of a medicalimplement and to decrease upon withdrawal of the medical implement suchas the syringe 1054 partially shown in phantom in FIG. 23. The crossmember 1022 has two longitudinal members 1056 rotatably attachedtogether. The cross member 1022 is disposed adjacent the central bodyportion 1048 of the reel 1020 within the inner cavity 1050 with thelongitudinal members 1056 preferably pointed toward the verticaldirection and desirably attached to the central body portion 1048 at itsfour ends 1058 as shown in FIG. 22. The longitudinal members 1056 rotateto a substantially horizontal orientation upon compression by theinsertion of the syringe 1054 as shown in FIG. 23. This rotation isreferred to as the deformation of the cross member 1022. Thelongitudinal members 1050 may be attached to rotate freely with respectto one another. Alternatively, the longitudinal members 1056 may bespring-loaded or attached such that they rotate under a rotational forcebut reform to their relaxed position upon release of the force. Uponwithdrawal of the syringe 1056 as shown in FIG. 22, the longitudinalmembers 1056 return to the substantially vertical positions, referred toas the reformation of the cross member 1022. The longitudinal members1026 are desirably longitudinal plates 1056 with sufficient width toopen up the central body portion 1048 of the reel 1020 in thesubstantially horizontal position but not so wide that they impedes flowtherethrough. Alternatively, they may contain holes (not shown) throughwhich fluid can pass.

FIG. 23 illustrates compression and FIG. 22 illustrates decompressionduring valve activation. In the compressed state, the syringe 1054 isplaced on the seal cap 1028 inside the opening 1062 of the housing 1012and the application of pressure on the syringe 1054 creates pressure onthe seal cap 1028. The downward pressure pushes the seal cap 1028 awayfrom the circular opening 1062 and toward the lower portion of thehousing 1012 which has a larger inner diameter, thereby allowing theprecut slit 1030 to open. The ring member 1018 moves toward the supportmember 1014 and compresses the resilient reel 1020. The upper flange1044 of the resilient reel 1020 is pushed by the ring member 1018 towardthe lower flange 1046. The central body portion 1048 bulges outwardly asthe cross member 1022 deforms, storing potential energy of thecompression. Fluid is able to flow into the syringe 1054, or vice versa,depending on whether fluid is to be withdrawn from the patient ormedication injected into the patient.

The compression of the seal 1016 and deformation of the cross 1022 shownin FIG. 23 generally causes a reduction in the volume of the innercavity of the seal 1016. The valve 1010 has a net gain in volume of theinner cavity 1050, however, because the expansion of the central bodyportion 1048 of the flexible reel 120 causes an increase in fluid volumewhich reduction resulting in is greater than the general contraction ofthe inner cavity 1050. The expansion results from the movement of thelongitudinal members 1056 of the cross member 1022 to open up thecentral body portion 1048 of the resilient reel 1020 during compression.

FIG. 22 illustrates the valve 1010 after withdrawal of the syringe 1054.The seal 1016 returns to its decompressed state and essentially fillsthe opening 1062, and the cross member 1022 reforms to allow the centralbody region 1048 of the resilient reel 1022 to narrow. Because of thecontraction of the inner cavity 1050 at the central body portion 1048,there is a net loss in fluid space, resulting in a positive flow fromthe valve 1010 through, e.g., a catheter tip (not shown). Thepositive-flow valve 1010 advantageously eliminates any dead space duringdecompression of the seal 1016. This is further assisted by the seal1016 with the slit 1030 remaining open until the very end, i.e., untilthe seal cap 1028 is squeezed by the circular opening 1062 at the top ofthe upper conduit 1066 of the housing.

In addition, the valve 1010 can be reused because the seal 1016 canreturn reversibly in the decompressed state. The seal surface 1068 isalso swabbable for sterility. Other features of the valve 1010 arediscussed previously in connection with the earlier embodiments of thisinvention.

Eleventh Embodiment

An eleventh embodiment of a valve 1110 in accordance with the presentinvention is illustrated in FIGS. 24 and 25, and comprises a valve bodyor housing 1112 and a seal 1114. The housing 1112 has an upper conduit1116 near a proximal end with a circular opening 1118 that is preferablyadapted to receive a medical implement such as a syringe 1120 partiallyshown in phantom in FIG. 25. The housing 1112 has a lower conduit 1124(partially shown) near a distal end which is connected to a fluid linesuch as a catheter (not shown). Disposed between the upper conduit 1116and lower conduit 1124 are protruded right and left side walls 1126 a,1126 b connected to resilient ribbed portions 1128 a, 1128 b which allowthe side walls 1126 a,1126 b to be stretched outwardly and reforminwardly in a substantially horizontal direction. Aside from theresilient ribbed portions 1128 a, 1128 b, the rest of the housing 1112is desirably made of a firm material such as a hard plastic.

The seal 1114 is generally similar to the seal 318 of FIG. 6 with asimilar shoulder 1132, seal cap 1134, and pressure responsive element1136. The cylindrical side wall 350 of FIG. 6, however, is replaced witha spreader 1140, which includes two legs 1142 a,1142 b that extend fromthe shoulder 1132 outwardly at distal ends 1144 a, 1144 b that bearagainst the protruded right and left side walls 1126 a, 1126 b, as bestseen in FIG. 24. The distal end 1144 a may be attached to the protrudedside wall 1126 a, and the distal end 1144 b may be attached to theprotruded side wall 1126 b, by adhesives or other available means. Aninner cavity 1150 is formed by the seal 1114 and a distal portion 1152of the housing 1112, and defines a fluid space of the valve 1110. Duringcompression of the seal 1114, the spreader 1140 extends furtheroutwardly and pushes the protruded side walls 1126 a,1126 b outwardly.The seal 1114 and housing 1112 are configured and dimensioned to assistin causing the fluid space to expand upon insertion of the medicalimplement 1120 and to contract upon withdrawal of the medical implement1120.

FIG. 25 illustrates compression and FIG. 24 illustrates decompressionduring valve activation. In the compressed state, the syringe 1120 isplaced on the seal cap 1134 inside the opening 1118 of the housing 1112and the application of pressure on the syringe 1120 creates pressure onthe seal cap 1134. The downward pressure pushes the seal cap 1134 awayfrom the circular opening 1118 and toward the lower portion of thehousing 1112 which has a larger inner diameter, thereby allowing theprecut slit 1156 oft he seal cap 1134 to open. The spreader 1140 extendsoutwardly, stretching the resilient ribbed portions 1128 a, 1128 b andpushing the protruded right and left side walls 1126 a, 1126 b of thehousing 1112 outwardly, storing potential energy of the compression.Fluid is able to flow into the syringe 1120, or vice versa, depending onwhether fluid is to be withdrawn from the patient or medication injectedinto the patient. The compression of the seal 1114 and deformation ofthe spreader 1140 shown in FIG. 36 results in a net gain in volume ofthe inner cavity 1150.

FIG. 24 illustrates the valve 1110 after withdrawal of the syringe 1120.The seal 1114 returns to its decompressed state and essentially fillsthe opening 1118, and the spreader 1140 and resilient ribbed portions1128 a,1128 b reform to allow the protruded right and left side walls1126 a,1126 b to move inwardly. Because of the contraction of the innercavity 1150, there is a net loss in fluid space, resulting in a positiveflow from the valve 1110 through, e.g., a catheter tip (not shown). Thepositive-flow valve 1110 advantageously eliminates any dead space duringdecompression of the seal 1114. This is further assisted by the seal 14with the slit 1156 remaining open until the very end, i.e., until theseal cap 1134 is squeezed by the circular opening 1156 at the top of theupper conduit 1116.

In addition, the valve 1110 can be reused because the seal 1114 canreturn reversibly in the decompressed state. The seal surface 1160 isalso swabbable for sterility. Other features of the valve 1110 arediscussed previously in connection with the earlier embodiments of thisinvention.

Twelfth Embodiment

A twelfth embodiment valve 1210 is illustrated in FIGS. 26 and 27, andcomprises a valve body or housing 1212, a support member 1214 (partiallyshown), a seal 1216, a ring member 1218, and a resilient reel 1226. Thehousing 1212, support member 1214, and ring member 1218 aresubstantially the same as those shown in FIGS. 22 and 23. The housing1212 has an upper conduit 1224 with a circular opening 1226. The supportmember 1214 has an inner conduit (not shown) which is connected to afluid line such as a catheter (not shown). The distal end 1228 of thering member 1218 contacts an upper flange 1232 of the resilient reel1220 and facilitates transfer of the compressive force due to insertionof a medical implement such as a syringe to cause deformation of thereel 1220. The reel 1220 further includes a central body portion 1234and a lower flange 1236 that is desirably supported and secured by thesupport member 1214.

The seal 1216 is similar to the seal 1114 of FIGS. 24 and 25, and has asimilar seal cap 1240 with slit 1242, shoulder 1244, and pressureresponsive member 1246. The seal 1246 has a spreader 1250 that extendsfrom the shoulder 1244 outwardly and forms a circular distal ring 1252that bears against the central body portion 1234 of the resilient reel1220, as best seen in FIG. 26. The distal ring 1252 may be attached tothe central body portion 1234 by adhesives or other available means. Aninner cavity 1254 is formed by the seal 1216 and a distal portion 1256of the resilient reel, and defines a fluid space of the valve 1210.During compression of the seal 1216, the spreader 1250 extends furtheroutwardly and pushes the central body portion 1234 of the resilient reel1220 outwardly. The seal 1216 and resilient reel 1220 are configured anddimensioned to assist in causing the fluid space to increase uponinsertion of a medical implement and to decrease upon withdrawal of themedical implement such as the syringe 1260 partially shown in phantom inFIG. 27.

FIG. 27 illustrates compression and FIG. 26 illustrates decompressionduring valve activation. In the compressed state, the syringe 1260 isplaced on the seal cap 1240 inside the opening 1226 of the housing 1212and the application of pressure on the syringe 1260 creates pressure onthe seal cap 1240. The downward pressure pushes the seal cap 1240 awayfrom the circular opening 1226 and toward the lower portion of thehousing 1212 which has a larger inner diameter, thereby allowing theprecut slit 1242 to open. The ring member 1218 moves toward the supportmember 1214 and compresses the resilient reel 1220. The upper flange1232 of the resilient reel 1220 is pushed by the ring member 1214 towardthe lower flange 1236. The central body portion 1234 bulges outwardly asthe spreader 1250 deforms and pushes the central body portion 1234outwardly, storing potential energy of the compression. Fluid is able toflow into the syringe 1260, or vice versa, depending on whether fluid isto be withdrawn from the patient or medication injected into thepatient.

The compression of the seal 1216 and deformation of the spreader 1250and reel 1220 shown in FIG. 27 causes an increase in volume of the innercavity 1254 because of the expansion of the central body portion 1234 ofthe flexible reel 1220. The expansion results from the movement of thespreaders 1250 to open up the central body portion 1234 of the resilientreel 1220 during compression.

FIG. 26 illustrates the valve 1210 after withdrawal of the syringe 1260.The seal 1216 returns to its decompressed state and essentially fillsthe opening 1226, and the spreader 1250 reforms to allow the centralbody region 1234 of the resilient reel 1220 to narrow. Because of thecontraction of the inner cavity 1254 at the central body portion 1234,there is a net loss in fluid space, resulting in a positive flow fromthe valve 1210 through, e.g., a catheter tip (not shown). Thepositive-flow valve 1210 advantageously eliminates any dead space duringdecompression of the seal 1216. This is further assisted by the seal1216 with the slit 1242 remaining open until the very end, i.e., untilthe seal cap 1240 is squeezed by the circular opening 1226 at the top ofthe upper conduit 1224.

In addition, the valve 1210 can be reused because the seal 1216 canreturn reversibly in the decompressed state. The seal surface 1266 isalso swabbable for sterility. Other features of the valve 1210 arediscussed previously in connection with the earlier embodiments of thisinvention.

Thirteenth Embodiment

A thirteenth embodiment valve 1310 in accordance with the presentinvention is illustrated in FIGS. 28 and 29. The valve 1310 comprises abody or housing 1312, a support member 1314 (partially shown), an upperseal 1316, and a lower seal 1318. The housing 1312 has an upper conduit1322 near a proximal end with a circular opening 1324 that is preferablyadapted to receive a medical implement such as a syringe 1326 partiallyshown in phantom in FIG. 40. The body 1312 has an upper side wall 1330distal to the upper conduit 1322 that is desirably circular in crosssection with a diameter larger than the diameter of the circular opening1324. The body 1312 has a lower side wall 1332 distal to the upper sidewall 1330 with a diameter larger than the diameter of the upper sidewall 1330. A middle conduit 1338 is advantageously formed between theupper side wall 1330 and lower side wall 1332. The upper side wall 1330is advantageously tapered from the upper conduit 1322 to the middleconduit 1338 and the lower side wall 1332 is advantageously tapered fromthe middle conduit 1338 to a distal end 1340 of the housing 1312. Themiddle conduit 1338 has a diameter larger than the diameter of the upperconduit 1322 and smaller than the diameter of the distal end 1340 of thehousing 1312.

The support member 1314 has at its distal end an inner conduit (notshown) which may be connected to a terminal of a catheter (not shown).The support member 1314 serves as a support and attachment device forthe upper and lower seals 1316, 1318 by holding the seals 1316, 1318 inplace inside the internal cavity 1346 of the housing 1312.

The upper and lower seals 1316, 1318 are prepared from a resilientmaterial that is flexible, inert, and impermeable to fluid, such assilicon. The upper seal 1316 has a seal cap 1350 with a generally flattop surface 1352, a shoulder 1354, a side wall 1356, and a base 1358.The side wall 1356 advantageously is comprised of ringed wall portions1360 which deform in an accordion-like fashion and assist in thereformation of the seal 1316 to enclose the housing opening 1324 uponwithdrawal of the syringe 1326. During compression of the upper seal1316, the diameter of the ringed wall portions 1360 expand outwardly inthe radial direction. The interior of the upper seal 1316 is hollow toprovide an upper inner cavity 1362, as best seen in FIG. 28. Theshoulder 1354 engages an upper ledge 1366 provided in the upper conduit1322 of the housing 1312 such that the upper ledge 1366 confines themovement of the shoulder 1354 toward the opening 1324 to prevent theupper seal 1316 from being blown through the opening 1324 under highpressure in the upper inner cavity 1362 of the seal 1316.

The seal cap 1350 of the upper seal 1316 reseals in the valve 1310 atthe opening 1324 with the top surface 1352 of the seal 1316 flush withor above the opening 1324 upon removal of the medical implement 1326.The seal cap 1350 substantially fills the opening 1324 in the top of theupper conduit 1322. It is preferred the top surface 1352 be exposedafter assembly so that it may be swabbed with alcohol or otherdisinfectant. The seal cap 1350 of the upper seal 1316 desirably has aunique shape with a precut slit 1370 such that the seal cap 1350 issqueezed shut by the opening 1324 when assembled and the slit 1370 opensautomatically during compression. The seal 1316 desirably also includesa pressure responsive member 1372 to further assist in creating afluid-tight seal in the decompressed state.

As shown in FIGS. 28 and 29, the lower seal 1318 desirably is generallysimilar to the upper seal 1316. The lower seal has a similar seal cap1380 with a generally flat top surface 1382, a shoulder 1384, and a sidewall 1386. The side wall 1386 defines a lower inner cavity 1390 and mayinclude similar ringed wall portions (not shown). The seal cap 1380 isdisposed at the middle conduit 1338 at the decompressed state andreseals the lower inner cavity 1390 at the middle conduit 1338 uponremoval of the medical implement 1326. The lower inner cavity 1390 formsa fluid space of the valve 1310, being in fluid communication throughthe lower conduit (not shown) to, e.g., a catheter (not shown). Thevalve components are configured and dimensioned to assist in causing thefluid space to increase upon insertion of the medical implement 1326 andto decrease upon withdrawal of the medical implement 1326.

The seal cap 1380 advantageously provides a fluid tight seal, having ashape and a precut slit 1394 similar to those of the upper seal 1316.The lower seal 1318 also includes desirably a pressure responsive member1396 similar to the pressure responsive member 1372 of the upper seal1316. The components of the lower seal 1318 are generally larger thanthose of the upper seal 1316 because of the geometry of the valvehousing 1312.

To illustrate valve activation, FIG. 29 shows the compressed state ofthe valve 1310 upon insertion of the syringe 1326. The syringe 1326 isplaced on the upper seal cap 1350 inside the opening 1324 of the housing1212. The application of pressure on the syringe 1326 creates pressureon the seal cap 1330, and the resulting downward pressure compresses theupper seal 1316. This pushes the seal cap 1350 away from the circularopening 1324 and toward the middle conduit 1338 at a region with alarger inner diameter, thereby allowing the precut slit 1370 to open.The downward movement is facilitated by the compression of the ringedwall portions 1360 of the side wall 1356 of the upper seal 1316. Thedownward force is transferred to the lower seal 1318 through the base1358 of the upper seal 1316 which cooperates with the seal cap 1380 ofthe lower seal 1318. The application of the pressure pushes the lowerseal cap 1380 away from the middle conduit 1338 and toward the lowerportion of the housing 1312 which has a larger inner diameter, therebyallowing the precut slit 1394 to open. Fluid is now able to flow intothe syringe 1326, or vice versa, depending on whether fluid is to bewithdrawn from the patient or medication injected into the patient. FIG.29 shows the valve 1310 opened by insertion of the syringe 1326 into theopening 1324.

In the compressed state shown in FIG. 29, the fluid space generallycontract under pressure from the decompressed state shown in FIG. 28.Upon removal of the syringe 1326 from the upper conduit 1322, as shownin FIG. 28, the upper and lower seals 1316,1318 are free to move towardtheir decompressed states. The movement normally would cause a generalexpansion of the fluid space. However, because of the fluidcommunication between the upper inner cavity 1362 and lower inner cavity1390, and the closing of the precut slit 1394 of the lower seal 1318upon compression, a decrease in volume results in the lower inner cavity1390 of the valve 1310. The decrease in the fluid space advantageouslygenerates a positive flow from the valve 1310 through, e.g., a cathetertip (not shown) to eliminate dead space. Advantageously, any dead spacewithin the upper inner cavity 1362 is also minimized since, as thesyringe 1326 is withdrawn, the slit 1370 remains open until the veryend, i.e., until the seal cap 1350 is squeezed by the circular opening1324 at the top of the upper conduit 1322. The elimination of backflashis particularly advantageous in the case where the valve 1310 isconnected through a catheter to a patient, because it prevents theintroduction of blood into the catheter.

As the upper seals 1316 is free to move to its decompressed state, itessentially fills the circular opening 1324. The ability of the upperseal 1316 to return reversibly to its decompressed state, together withthe resiliency of the lower seal 1318, permits the reuse of the valve1310. Following disconnection, and before reuse, the surface 1352 of theseal cap 1316 is essentially flush with the opening 1324 of the housing1312. Thus, this flush surface 1352 can advantageously be sterilizedwith alcohol or other surface decontaminating substances. A cover cap(not shown) can further be used to fit over the upper conduit to protectthe surface 1352 of the seal cap 1350.

Fourteenth Embodiment

A fourteenth embodiment of a valve 1410 of the present invention isillustrated in FIGS. 30 and 31, and comprises a valve body or housing1412, a seal 1414, a piston 1416, and a spring 1418. The housing 1412has an upper conduit 1420 near a proximal end with a circular opening1422 that is preferably adapted to receive a medical implement such as asyringe 1423 partially shown in phantom in FIG. 31. The housing 1412 hasa side conduit 1424 which is connected to a fluid line such as acatheter (not shown). Disposed in a lower chamber 1426 of the housing1412 is the spring 1418 supporting the piston 1416 which bears against adistal end 1430 of the seal 1414 disposed in an upper chamber 1432 ofthe housing 1412. The lower chamber 1426 of the housing 1412advantageously includes an orifice 1434 for venting the air therein tofacilitate movement of the spring 1418. The upper chamber 1432 and lowerchamber 1426 expand and contract according to the movement of the piston1416 under pressure from the seal 1414 and the spring 1418. The housing1412 advantageously includes a side aperture 1438 additional fluid to betransferred to the patient through the upper chamber 1432 and sideconduit 1424 when necessary.

The seal 1414 has seal cap 1442 with precut slit 1444, a shoulder 1446,and a pressure responsive member 1448. The seal has a side wall 1450which defines an inner cavity 1452 and has the distal end 1430 thatcooperates with the piston 1416 for efficient transfer of pressurebetween them. Near the distal end 1430 of the seal 1414 is desirably atransverse fluid passage 1456 for fluid communication between the seal1414 and the upper chamber 1432. Although FIGS. 30 and 31 illustratethat the transverse fluid passage 1456 also facilitates fluid flowbetween the side aperture 1438 and the side conduit 1424, it need not doso if fluid can flow around the seal 1414 in the upper chamber 1432. Theupper chamber 1432 and the inner cavity 1450 of the seal 1414 forms thefluid space of the valve 1410.

FIG. 31 illustrates compression and FIG. 30 illustrated decompressionduring valve activation. In the compressed state, the syringe 1423 isplaced on the seal cap 1442 inside the opening 1422 of the housing 1412and the application of pressure on the syringe 1423 creates pressure onthe seal cap 1442. The downward pressure pushes the seal cap 1442 awayfrom the circular opening 1422 and toward the lower portion of thehousing 1412 which has a larger inner diameter, thereby allowing theprecut slit 1444 to open. The side wall 1450 moves further into theupper chamber 1432 and pushes the piston 1476 downward against thespring 1418, which is compressed, storing potential energy of thecompression. Fluid is able to flow into the syringe 1423, or vice versa,depending on whether fluid is to be withdrawn from the patient ormedication injected into the patient. The compression of the seal 1414shown in FIG. 31 generates a net gain or increase in volume of the fluidspace of the valve 1410.

FIG. 30 illustrates the valve 1410 after withdrawal of the syringe 1423.The seal 1414 returns to its decompressed state and essentially fillsthe opening 1422, and the piston 1416 moves back to its decompressedposition as the spring 1418 releases its potential energy. Because ofthe contraction of the upper chamber 1432 of the housing 1412, there isa net loss in fluid space, resulting in a positive flow from the valve1410 through, e.g., a catheter tip (not shown). The positive-flow valve1410 advantageously eliminates any dead space during decompression ofthe seal 1414. This is further assisted by the seal 1414 with the slit1444 remaining open until the very end, i.e., until the seal cap 1442 issqueezed by the circular opening 1422 at the top of the upper conduit1420.

In addition, the valve 1410 can be reused because the seal 1414 canreturn reversibly in the decompressed state. The seal surface 1460 isalso swabbable for sterility. Other features of the valve 1410 arediscussed previously in connection with the earlier embodiments of thisinvention.

Additional Embodiments

Additional embodiments of the present invention are contemplated withoutdeparting from the spirit and scope of the present invention. Forinstance, the volume inside a straight tubing contracts when the tube isbent. Thus, one valve embodiment valve may have a fluid space inside astraight tubing which bends upon insertion of a medical implement andreforms upon withdrawal of the medical implement, thereby effectingpositive flow.

In addition, many of the ringed side wall of the seals (such as theportions 1360 of the seal 1316 of FIG. 28) can be replaced by circulartires 1580 stacked in series one on top of an adjacent larger-diameterlower tire, as illustrated in FIG. 32. The circular tires 1580 arepreferably solid throughout the diameter of the cross-section thereof.Like the ringed side wall portions 1360, these circular tires 1580 willdeform and reform upon, respectively, compression and decompression ofthe seal.

CONCLUSION

In the embodiments described above, the fluid space inside the valveincreases upon insertion of a medical implement in the compressed stateand decreases upon withdrawal of the medical implement in thedecompressed state. In some embodiments, the structure defining thefluid space is substantially relaxed and does not store substantialamount of potential energy. Insertion of the medical implement causes achange in the structure that allows it to store potential energy. Thepotential energy is released upon withdrawal of the medical implementand the structure returns to a substantially relaxed condition. In otherembodiments, at least some components of the structure defining thefluid space stores potential energy under strain or deformation. Uponinsertion of a medical implement in the compressed state, the potentialenergy in those components is released and is stored in other componentsof the structure or in another form. The stored potential energy in thecompressed state is released when the medical implement is removed, andthe original potential energy is restored in the structure.

The above presents a description of the best mode contemplated ofcarrying out the present invention, and of the manner and process ofusing it, in such full, clear, concise, and exact terms as to enable anyperson skilled in the art to which it pertains to make and use thisinvention. This invention is, however, susceptible to modifications andalternate constructions from that discussed above which are fullyequivalent. In particular, many of the features of the co-pendingapplications, serial nos. and can be incorporated into the presentinvention, and these applications are incorporated herein by reference.The embodiments described are meant to be illustrative and notexhaustive. Consequently, it is not the intention to limit thisinvention to the particular embodiments disclosed. On the contrary, theintention is to cover all modifications and alternate constructionscoming within the spirit and scope of the invention as generallyexpressed by the following claims, which particularly point out anddistinctly claim the subject matter of the invention.

What is claimed is:
 1. A medical valve for controlling the flow of fluidbetween a medical implement and a catheter tip of a catheter in fluidcommunication with said valve, said valve comprising a body having acavity with an outlet adapted to be connected in fluid communicationwith a catheter tip and an opening adapted to receive a medicalimplement, and a seal positioned within said body and movable between afirst position in which fluid flow is permitted through said opening anda second position in which said seal obstructs fluid flow through saidopening, said cavity including a first fluid space open to said outletwhen said seal is in said first position and a second smaller space opento said outlet when said seal is in said second position.
 2. The medicalvalve in accordance with claim 1, wherein said seal has a first end anda second end and a passage therethrough, said passage occluded when saidseal is in said second position.
 3. The medical valve in accordance withclaim 1, wherein said body has a proximal end and a distal end, andwherein said seal moves distally within said body to said first positionwhen a medical implement is inserted through said opening.
 4. Themedical valve in accordance with claim 1, further including biasingmeans for biasing said seal into said second position.
 5. The medicalvalve in accordance with claim 4, wherein said biasing means comprises aspring.
 6. The medical valve in accordance with claim 1, furtherincluding a flow control member which reversibly contracts said fluidspace in said second position and expands said fluid space in said firstposition.
 7. The medical valve in accordance with claim 6, wherein saidflow control member comprises a portion of said seal.
 8. A positive-flowmedical valve comprising a body including a wall structure defining aninternal cavity having a proximal end and a distal end, said proximalend having an opening sufficiently large to receive a delivery end of amedical implement which transfers fluid through said delivery end; aresilient seal which is adapted to be moved into a compressed state uponinsertion of a delivery end of a medical implement into said opening andreturns to a decompressed state upon removal of said delivery end, saidseal in a decompressed state having a section which fills essentiallycompletely a portion of said cavity adjacent said opening, with saidseal section bearing against said wall structure near said opening toseal said opening, and in a compressed state said seal section beingpushed by the delivery end of the medical implement away from saidopening and into said cavity, said seal having a hollow interior andincluding an orifice in said seal section which is open in a restingstate but is kept closed by said opening in said decompressed state; afluid space including at least a portion of said hollow interior anddisposed at least partially in said cavity; and a flow control memberwhich reversibly contracts said fluid space in said decompressed stateand expands said fluid space in said compressed state.
 9. The valve inaccordance with claim 8, wherein said flow control member comprises aportion of said seal.
 10. The valve in accordance with claim 8, furtherincluding means for biasing said seal towards said decompressed state.11. The valve in accordance with claim 10, wherein said means comprisesa spring.
 12. The valve in accordance with claim 10, wherein said meanscomprises a pair of cross-members.
 13. The valve in accordance withclaim 8, wherein said wall is movable and said fluid space comprisespartly said cavity defined by said wall.
 14. A medical valve forcontrolling the flow of fluid between a medical implement and a cathetertip of a catheter in fluid communication with said valve, said valvecomprising a body having a cavity in fluid communication with thecatheter tip and an opening adapted to receive the medical implement, amoveable wall forming a wall of said cavity, and a seal positionedwithin said body, said seal configured to permit fluid to flow throughsaid seal and movable between a first position in which fluid flow ispermitted through said opening and a second position in which said sealobstructs fluid flow through said opening, said cavity including a fluidspace which automatically and reversibly increases in size when saidseal is moved to said first position and which contracts in size whensaid seal is moved to said second position.
 15. The valve of claim 14including a resilient member urging the wall to move in a direction todecrease said space.
 16. A medical valve for controlling the flow offluid between a medical implement and a catheter tip of a catheter influid communication with said valve, said valve comprising a body havinga cavity to be in fluid communication with a catheter tip and an openingadapted to receive the medical implement, a seal positioned within saidbody and movable between a first position in which fluid flow ispermitted through said opening and a second position in which said sealobstructs fluid flow through said opening, said cavity including a fluidspace which automatically and reversibly increases in size when saidseal is moved to said first position and which contracts in size whensaid seal is moved to said second position, and said body having aninlet adapted to receive another medical implement, said inlet being influid communication through said cavity to said outlet with said seal ineither of said first or second positions.
 17. A medical devicecomprising: a housing having a cavity with a first inlet for fluid flowinto the cavity, and an outlet for connection to a catheter leading to apatient; said housing having a second inlet for receiving a medicalimplement to introduce fluid into the cavity; a valve element having afirst position closing said second inlet and a second position in whichsaid valve element is moved by said implement into a position in whichsaid second inlet is open to said outlet while said first inlet remainsopen for fluid flow to said outlet, said valve element being configuredto cause the volume of said cavity to increase when moved from saidfirst position to said second position and to cause said volume todecrease when moved to said first position.
 18. The device of claim 17including a movable wall in said cavity, which is movable by saidelement to increase the volume of the cavity.
 19. The device of claim 18including a resilient member urging said wall in a manner to decreasethe volume of the cavity.
 20. The device of claim 19, wherein said wallis a piston and said resilient member is a spring.
 21. A method ofcausing a positive flow of fluid through a catheter tip automaticallyupon disconnection of a first medical implement from a valve having ahousing with a moveable element therein for controlling the flow offluid through said housing, said element defining a fluid volume withinsaid housing and said valve in communication with said catheter tip,said housing connectable to a second medical implement wherein anuninterrupted flow of fluid is permitted from the second medicalimplement through said valve and to the catheter tip when the secondmedical implement is connected to said valve, comprising the steps of:disconnecting said first medical implement form said valve; and movingsaid moveable element to a position in which fluid flow between saidvalve and said implement is prevented; decreasing the fluid volumewithin said valve housing; and forcing fluid from said housing towardssaid catheter tip.
 22. A method of delivering fluid through a cathetertip comprising the steps of: providing a valve having a housing with aninlet and an outlet in communication with said catheter tip, saidhousing having an opening closed by a movable element; flowing fluidfrom said inlet to said outlet; connecting a medical implement to saidopening and moving said element into a position in which the fluidvolume in said housing is increased; injecting fluid from said implementinto said housing and to said outlet, while fluid communication fromsaid inlet to said outlet remains open; disconnecting said medicalimplement from said valve; moving said moveable element to a position inwhich fluid flow from said implement into said housing is prevented,while fluid flow from said inlet to said outlet is permitted; decreasingthe fluid volume within said valve housing; and forcing fluid from saidhousing towards said catheter tip.